1. Technical Field
The present invention relates to an electrical connector having a holddown attached to a housing and fixed to a circuit board.
2. Related Art
In related art, electrical connectors mounted on circuit boards in engagement with counterpart connectors and adapted to fix fittings called holddowns attached to housings to the circuit boards on which the electrical connectors are mounted are known.
FIG. 12 is a perspective view of an electrical connector of the related art, and FIG. 13 is a perspective view of holddowns of the related art.
The electrical, connector 200 of the related art shown in FIG. 12 includes a housing 202 and a pair of holddowns 210. The electrical connector 200 also has an inner housing (not shown) to which a contact is attached in addition to the housing 202.
The housing 202 has a protrusion 201 that protrudes from a circuit board and engages with a counterpart connector when the electrical connector 200 is mounted on the circuit board. The housing 202 also has a pair of left and right grooves 203 open at the top surface.
The holddowns 210 each have a held part 211 having left and right ends bent toward the same side and held in the groove 203 of the housing 202, and a leg part 212 extending vertically from the held part 211 as shown in FIG. 13. The holddowns 210 are press-fitted into the grooves 203 of the housing 202 from above so that the held parts 211 are held in the grooves 203, and lower ends of the held parts 211 are in contact with inner bottom faces, which are not shown, of the grooves 203 so that the holddowns 210 are prevented from coming off the housing 202 downward. The leg parts 212 of the holddowns 210 protrude outward from the bottom face of the housing 202 and are fixed to the circuit board by soldering.
As a result of fixing the holddowns 210 held by the housing 202 to the circuit board as described above, the strength against a load such as prying force applied on the housing 202 when the counterpart connector is engaged with the housing 202 can be improved.
The electrical connector 200 of the related art shown in FIG. 12, however, has an eccentric center of gravity closer to the protrusion 201 and is thus tilted in the R direction in FIG. 12 when placed on the circuit board. The electrical connector 200 thus needs to be soldered in a state in which the electrical connector 200 is pressed with a jig or the like. In particular, the protrusion 201 needs to serve as a guide for insertion when the counterpart connector is engaged and to hold the counterpart connector so as not to come off after engagement, and thus needs to have a sufficient length in the protruding direction. The electrical connector 200 of the related art shown in FIG. 12 therefore has a problem that the center of gravity is likely to be closer to the protrusion 201.
In such circumstances, JP 10-340767 A and JP 10-172632 A disclose electrical connectors with a center of gravity adjusted when the electrical connectors are mounted on circuit boards so that tilting in soldering due to eccentricity of the center of gravity can be prevented.
Specifically, JP 10-340767 A discloses an electrical connector in which a connector body is accommodated in a housing in a state in which the connector body can slide in the front-back direction and a contact lead and a soldering lead provided in the connector body are connected by a flexible cable. In JP 10-340767 A, this allows adjustment of the center of gravity by sliding the connector body.
JP 10-172632 A discloses an electrical connector in which a balance weight is placed on a position opposite to the center of gravity of the entire housing in the front-back direction with respect to the center in the front-back direction of the bottom face of the housing in a mounted state. In JP 10-172632 A, this allows the center of gravity in the front-back direction of the housing to be adjusted closer to the center in the front-back direction of the bottom face in the mounted state, which allows the electrical connector to be stably mounted on a circuit board before soldering.